Nowadays, batteries of portable consumer devices such as mobile phones and MP3-players are typically charged by a charging device via a Universal Serial Bus Micro-USB power connection. Following a request from the European Commission, major producers of mobile phones have for instance agreed in a Memorandum of Understanding to harmonise charging devices for data-enabled mobile phones sold in the European Union on the basis of Micro-USB power connection. Accordingly, a single charging device may be used for charging more than one of these portable devices.
In the field of medical devices often more strict (governmental) regulations and (industry) standards apply than in the field of consumer devices. For instance, European Standard EN 60101-1 requires a double insulation between the medical device and the main voltage. To comply with these regulations and standards, batteries of portable medical devices are typically charged by a proprietary charging device via a proprietary power connection.
Use of such a proprietary charging device is however inconvenient for users, because the charging device may only be used for charging a battery of a single portable medical device. Furthermore, the proprietary charging device may become worthless, when the corresponding portable medical device is broken.